Adjustable fuel nozzle



lJuly 7, 1959 D. E. wom-MAN ADJUSTABLEFUEL. NozzLE 2 Sheets-Sheet 1 Filed May 6, 1957 lll ATTORNEY July4 7, 1959 D. E. WORTMAN 2,893,647

` ADJUSTABLE FUEL NOZZLE I Filed May 6, 1957 2 Sheets-Sheet `2 INVENTOR.

ATTORNEY United States Patent O ADJUSTABLE FUEL NOZZLE Donald E. Wortman, Grand Rapids, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application May 6, 1957, Serial No. 657,121

6 Claims. (Cl. 239-464) This invention relates to spray nozzles and more particularly to an arrangement whereby adjustment of the nozzle may be readily had.

In spray nozzles, in particular liquid fuel spray nozzles of the type used in gas turbine engines, it is common to have a spring biased valve i-n the nozzle to control the flow of fuel. The valve is located in the main fuel flow passage and is spring loaded to closed position so that fuel will not iiow in the main fuel passage until sucient liuid pressure is built up. The valve may, in addition, incorporate a metering orifice to regulate fuel iiow in accordance with changes in fuel pressure.

It is desirable that the valve spring loading of such fuel nozzles be precisely and readily adjustable for many reasons. It is also desirable Ithat such adjustment may be had without disassemblng any of the various parts of the nozzle in the interest of speed and because re-assembly after a disassembled adjustment might disturb the adjustment.

It is iaccordingly an object of the invention to provide a precise and ready means for adjusting a spray nozzle.

It is accordingly a further object of the invention to provide a spray nozzle which may be quickly adjusted without the disassembly of any portion of the nozzle.

Further objects and advantages of the invention will be apparent from the following description, reference being made to the accompanying drawings, wherein a preferred form of the invention is clearly shown.

In the drawings: t t Y Figure l is a partial section through a gas turbine combustor showing the inventive nozzle in side elevation;

Fig. 2 is an enlarged longitudinal or axial section through the nozzle;

Figure 3 is an enlarged longitudinal elevation of the nozzle partially broken away and illustrating the adjustment thereof by the simple insertion of a conventional tool; Y

Figure 4 is a partial transverse section through the nozzle taken substantially on the plane indicated by the line 4 4 of Figure 2; and Figure 5 is a partial transverse section through the nozzle taken substantially on the plane indicated by the line y 5 5 of Figure 3.

Referring to the drawings, a liquid fuel spray nozzle assembly 10 is sho'wn installed in the combustor of a gas turbine engine which combustor includes an air delivery portion 12, a llame tube 14 and a combustion chamber air jacket 16; the nozzle being arranged to spray a cone `of atomized fuel into the flame tube for combustion therein with the air supplied by the air supply portion 12 and air jacket 16. The nozzle includes a fuel supply elbow 18 to which is secured a nozzle outer body 20 by threads 22. An air director cap 2,4 is secured to the Vdischarge end of the nozzle by threads 26 and a nozzle inner body 28 is secured in the nozzle outer body 20 by threads 30.V A metering and cutoff valve 32 is reciprocably carried in the inner body 28 and is biased into .Off position by ia compression spring 34 which engages an 2,893,647 Patented July 7, 1959 ICC abutment member 36 at one end and a disk 38 at the other; a cap 40 being secured by threads 42 to the intake end of the inner body to retain the valve therein.

A spray tip 44 is secured at the discharge end of the outer body 20 by the discharge end of the inner body 28 and has a swirl chamber 46 that communicates with a fuel discharge orifice 48 and has a wall 50 that has an aperture 52 aligned with and facing the discharge orifice.

An anchor member 54 is secured to the spray tip 44 and has a rearwardly projecting hexagonal surface 55 upon which is slidably mounted the abutment member 36 by a complementary hexagonal surface 56. The abutment member 36 is thus free to shift axially on the anchor member 54 but is restrained against rotation thereby.

A lock member 58 has one end threaded into the abutment member 36 at 60 and the other end formed with a head portion that has a hexagonal outer surface 62 and a hexagonal cavity 64 which is aligned with the wall aperture 52. The hexagonal outer surface 62 is received in a twelve-sided cavity 66 in the anchor member 54 so that the lock member 58 is non-rotatable as long as it is engaged. The lock member S8 may be axially shifted to disengage the head portion from the cavity 66 whereupon rotation of the lock member 58 can be effected to advance the abutment member 36 along the threaded connection 60, the abutment member 36 being restrained against rotation by its hexagonal connection 55, 56 with the anchor member 54.

The advance of the `abutment member 36 affords a means for changing the spring bias on the valve 32 and is accomplished by inserting a suitable tool, such as the hexagonal wrench 65, through the spray tip orifice 48, swirl chamber 46 and wall aperture 52 for engage ment in the lock member cavity 64 to shift the lock member axially and thereafter turn it. Adjustment may be quickly made and Without disassembling the nozzle in any manner, and the arrangement provides for a very fine adjustment of the spring force since the lock member head 62 can be inserted in the anchor cavity 66 in any of the l2 rotary portions whereby the abutment member 36 may be advanced Yalong the thread 60 of the lock member 58 in less than whole thread increments.

In operation, fuel under pressure is supplied to the nozzle through a passage 70 in the elbow 18 and thence through a filter 72 Ito a chamber 73 and then into a passage 74 in the valve 32. The filter 72 engages the outer body 20 at one end and a spring 76 at the other end which spring abuts against a washer 78 which is secured in the elbow 18. The valve 32 has a triangular shaped metering orifice 80 in the side wall thereof and this orilice is gradually uncovered to place the passage 74 in communication with a chamber 82 in the inner body 28 as fluid pressure overcomes the spring bias. A plurality of tangential passages 84 extend through the cylindrical portion of the spray tip 44 to place the swirl chamber 46 in communication with the chamber 82 whereby fuel is supplied -to the swirl chamber for discharge and atomization out the discharge orifice 48. The spray tip 44 is also provided with a plurality of smaller tangential passages 86 which are in direct communication with the chamber 73 by way of a longitudinally grooved passage 88 in the thread 30 and an annular space 90 around the outer surface of the inner body 2S so that a small amount 'of fuel can be sprayed without unloading the valve 32. This small amount of fuel is provided to start the engine. The air director cap 24 directs an air stream at the fuel as it emerges from the discharge orifice 48. The director cap 24 communicates with compressed air in the combustor portion 12 and longitudinal slots 92 are provided in the thread 26 to feed air to a plurality of air discharge passages 94 and 96. Y

The fuel is apt to contain some grit of such fineness vasesinan' as to make it impractical for the strainer 72 to remove it. The strainer`72 is accordingly designed to remove larger grit particles and the'iine grit is run through the nozzle. There is a tendency for ne grit, however, to work'betweenthe outer surface of the valve 32 and the complementary boreinlthe inner body '28 and'-these mating rubbing surfaces are accordingly bathed with clean fuel to preventthis. 'A very fine flter 981eucircles the inner body 2S and supplies clean fuel to radial passages v100 therein. This clean .or finely-filtered fuelbathes the periphery of the valve 32 and is ata slightly higher pressurethan' the main fuel flow. in the valve passage 74 due to a flowV pressure drop in the main fuel ow caused by a restrictor passage 102 in the cap 40. This protectiveV ltering system; is specicallydescribed'and claimed in Patent No. 2,734,523, `Wiggans.

While the preferred Yemlzaodiment of the invention has been described fully in order toexplain the principles of the inventiom'it is'to beunderstoodthat modifications of structure may be made by the exercise of skill in the art within the scope of the invention which is not to be regarded as limited by the detailed description of the preferred embodiment.

I claim:

l. A liquid fuel spray nozzle that is adapted for adjustment byfa tool that is insertible in the discharge oriiice of a nozzle, the nozzle comprising a body having a passage formed therein, a valve in the body for closing the passage, a spray tip in one end of the body including a swirl chamber communicating with the passage downstream of the valve, the spray tip having a discharge orifice on one side of the swirl chamber and a wall on the other side of the swirl Vcharnber with an aperture formed therein in alignment withV and facing the discharge orice, an adjustable abutment means in the body adjacent the spray'tip and including a tool/reception portion in alignment with and accessible through the aperture and orifice for engagement and adjustment by the insertible tool, and spring means in the body connecting the valve and abutment means to vary the valve loading in accordance with adjustment of .the abutment means by the tool.

2. A liquid fuel spray nozzle that is adapted for adjustment by a tool that is insertible in the discharge orifice of the nozzle, the nozzle comprising a body'having a passage formed therein, a valve in the body for closing the passage, a spray tip in the body including a swirl chamber communicating with the passage downstream of the valve, the spray tip having a discharge orifice on one side of the swirl chamber and an adjustable abutment means on the other side of the swirl chamber including atool'reception portion in alignment with and facing the discharge oriiice, said tool reception portion being accessible Ithrough said orifice for engagement and adjustment bythe insertible tool, and spring means in the body connecting the valve and abutment means to vary the valve loading in accordance with adjustment of the abutment means by the tool.

3. An adjustable abutment arrangement for valve springs and the like comprising an anchor member, an abutment member axially shiftable and non-rotatably mounted thereon, a lock member having a threaded connection in said abutment member and being movable into axially shiftable engagement in said 'anchor member and being restrained against rotation by. said anchor member when engaged, and spring means engaging said abutment member to bias said lock memberl into engagement in said anchor member whereby said abutment member is axially positioned, said arrangement affording means whereby said abutment member may be adjusted and locked to a new. axial position to vary the `loading on said spring means by axially shifting said lock member. against said spring means todisengage said lock member from said anchor member, by thereafter. rotating saidlock .member to advance said abutment member through said threaded connection and by thereafter axially shifting said lock member by means of said spring means to eiect reengagement of said lock member in said anchor member.

4. A liquid spray nozzle that is adapted for adjustment by a tool that is insertible in the discharge orifice of the nozzle, the nozzle comprising a body having a discharge oriiice therein, said body having a passage formed therein for supplying' liquid to said orifice, a valve in said bodyyffor :controlling-said passage, an adjustable abutment means in said: body' including a head portion aligned with said orifice in spaced relation thereto, and-a spring in said body connecting said abutment means and said valve, said head portion being accessible through said orifice for engagement by the insertible tool to move said abutment means and vary the spring load on said valve.

5. A liquid spray nozzle that is adapted for adjustment by a tool that is insertible, in the discharge oriiice ofthe nozzle, the. nozzle comprising a body having a discharge oriiice therein, said body having a passage formed therein for supplying liquid lto'said orifice, a valve in said body for controlling said passage, a threaded member in said body including a head, portion aligned with said orifice in spaced relation thereto, and a spring in said body operatively connecting said threaded member and said valve, said head portion being accessible through said oric a forengagement by the insertible tool to rotate said threaded member. and vary the spring load on said valve.

6. vA liquid fuel spray nozzle that is adapted for adjustment bya tool that is insertible in the discharge oriceof the nozzle, the nozzle comprising a body having a passage .formed therein, a valve in the body for closing the passagea spray tip in one end of the body including a swirl chamber communicating with the passage downstream of the valve, the spray tip having a discharge orifice on one side of the swirl chamber and a wall on the other side ofthe swirl chamber with anapertureformed therein in alignment with and facing the discharge orifice, an adjustable lock member in the body adjacent vthe spray Itip wall including a tool reception portionin alignment with and accessible through the spray tip aperture vand orifice for engagement and `adjustment by the insertible tool, an anchor member in the body secured to the spray tip, an abutment member in the body axially shiftable and non-rotatably mounted on the anchor member, the lock member having a threaded connection in the abutment member and being movable into axially shiftablc engagement in the anchor member and beingrestrained against rotation by the anchor member when engaged, and spring means in the body connecting -the valveand the abutment member to bias the associated lock member into engagement in the anchor memberwhereby the abutment member is axially positioned, said arrangement affording means whereby the `abutment member may be adjusted and locked to a new *axial` position on Vthe anchor member and lock member to vary the loading on the spring means by inserting the tool through the aperture .and orifices and into engagement with thetool reception portion and by axially shifting the tool and lock member and associated abutment memberv against the spring means to disengage the lock member from the anchor member, by thereafter rotating the tool and Vlock member to advance the abutment ,member through the threaded connection and by thereafter removing the ftool to effect reengagement of thelock member in the anchor member by the spring means.

References Cited in the file of this patent 

